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The 14-carbon in animal tissues records the time that the tissues are formed; since the 1960s, using the “bomb curve” for 14 C, the age of animal death can be determined accurately. Using animal tissue samples of known collection and formation dates for calibration, we determine the age of ivory samples from four ivory seizures made by law enforcement agencies between 2017 and 2019. The 14 C measurements from these seizures show that most ivory in the illegal wildlife trade is from animals from recent poaching activities. However, one seizure has a large fraction of ivory that is more than 30 y old, consistent with markings on the tusks indicating they were derived from a government stockpile. 

Breath and diet samples were collected from 29 taxa of animals at the Zurich and Basel Zoos to characterize the carbon isotope enrichment between breath and diet. Diet samples were measured for δ 13 C and breath samples for CH 4 /CO 2 ratios and for the respired component of δ 13 C using the Keeling plot approach. Different digestive physiologies included coprophagous and non-coprophagous hindgut fermenters, and non-ruminant and ruminant foregut fermenters. Isotope enrichments from diet to breath were 0.8 ± 0.9‰, 3.5 ± 0.8‰, 2.3 ± 0.4‰, and 4.1 ± 1.0‰, respectively. CH 4 /CO 2 ratios were strongly correlated with isotope enrichments for both hindgut and foregut digestive strategies, although CH 4 production was not the sole reason for isotope enrichment. Average CH 4 /CO 2 ratios per taxon ranged over several orders of magnitude from 10 –5 to 10 –1 . The isotope enrichment values for diet-breath can be used to further estimate the isotope enrichment from diet-enamel because Passey et al. (2005b) found a nearly constant isotope enrichment for breath-enamel for diverse mammalian taxa. The understanding of isotope enrichment factors from diet to breath and diet to enamel will have important applications in the field of animal physiology, and possibly also for wildlife ecology and paleontology. 

Comparative morphometric study of recently recovered fossil elephant molars from Natodomeri, Kenya identifies them as belonging to Elephas jolensis and confirms the presence of this species in Members I and II of the Kibish Formation. Improved datation of these geological units constrains them between 205 and 130 ka. Elephas jolensis is also reported from localities in northern, northwestern, eastern, and southern Africa. Thus, including its Natodomeri occurrence, E. jolensis appears to have been pan- African in distribution. Despite the wide geographic distribution of the species, molars of E. jolensis are remarkably uniform morphometrically. They are characterized by their extreme hypsodonty, high amplitude of enamel folding, high lamellar frequency, and plates that are anteroposteriorly thick relative to transverse valley interval spacing. In addition, they exhibit only a modest number of plates (<20 in M3/m3). Elephas jolensis either evolved from or represents the last stage of Elephas recki, the dominant elephant species in East Africa during the late Pliocene-Pleistocene. The dental morphology and isotopic composition of E. jolensis indicates that, like E. recki, it was a dedicated grazer. In the Kibish Formation, E. jolensis is succeeded by Loxodonta africana at 130 ka, coincident with an intensely cool, dry interval marked by episodes of extreme drought. This marked the extirpation of Elephas on the continent. The intensity and increased rate of climate fluctuation may have played an important role in the demise of the specialist, grazing E. recki-E. jolensis lineage in favor of a generalist, mixed feeder such as L. africana. Keywords Natodomeri, Kenya . Kibish Formation . Elephantidae . Elephas jolensis . Late middle Pleistocene